We have a Parenting site that has a bullying tag
Helping your child deal with being bullied or dealing with your child who is exhibiting bullying behavior.
We've also a Workplace site with that same tag for
Questions relating to abusive / intimidating behaviour in the workplace
Jon Custer points out that Interpersonal skills also has a bullying tag
When someone is hurt or frightened by someone who is bigger or more powerful, and is trying to force them to do something that they do not want to do.
There are questions about bulling on the Psychology site but there's no bullying tag. Instead they seem to use the human-factors or social-psychology tags.
As always check out the site's help centres to check your question would be on-topic.
If you want to propose your own site there's a process for that but you really need a community of people who can get that site off the ground with you. Creating a new site costs nothing.